Class

GtkIMContext

Description [src]

abstract class Gtk.IMContext : GObject.Object {
  parent_instance: GObject
}

GtkIMContext defines the interface for GTK+ input methods. An input method is used by GTK+ text input widgets like GtkEntry to map from key events to Unicode character strings.

The default input method can be set programmatically via the GtkSettings:gtk-im-module GtkSettings property. Alternatively, you may set the GTK_IM_MODULE environment variable as documented in [Running GTK+ Applications][gtk-running].

The GtkEntry GtkEntry:im-module and GtkTextView GtkTextView:im-module properties may also be used to set input methods for specific widget instances. For instance, a certain entry widget might be expected to contain certain characters which would be easier to input with a certain input method.

An input method may consume multiple key events in sequence and finally output the composed result. This is called preediting, and an input method may provide feedback about this process by displaying the intermediate composition states as preedit text. For instance, the default GTK+ input method implements the input of arbitrary Unicode code points by holding down the Control and Shift keys and then typing ā€œUā€ followed by the hexadecimal digits of the code point. When releasing the Control and Shift keys, preediting ends and the character is inserted as text. Ctrl+Shift+u20AC for example results in the ā‚¬ sign.

Additional input methods can be made available for use by GTK+ widgets as loadable modules. An input method module is a small shared library which implements a subclass of GtkIMContext or GtkIMContextSimple and exports these four functions:

void im_module_init(GTypeModule *module);

This function should register the GType of the GtkIMContext subclass which implements the input method by means of g_type_module_register_type(). Note that g_type_register_static() cannot be used as the type needs to be registered dynamically.

void im_module_exit(void);

Here goes any cleanup code your input method might require on module unload.

void im_module_list(const GtkIMContextInfo ***contexts, int *n_contexts)
{
  *contexts = info_list;
  *n_contexts = G_N_ELEMENTS (info_list);
}

This function returns the list of input methods provided by the module. The example implementation above shows a common solution and simply returns a pointer to statically defined array of GtkIMContextInfo items for each provided input method.

GtkIMContext * im_module_create(const gchar *context_id);

This function should return a pointer to a newly created instance of the GtkIMContext subclass identified by context_id. The context ID is the same as specified in the GtkIMContextInfo array returned by im_module_list().

After a new loadable input method module has been installed on the system, the configuration file gtk.immodules needs to be regenerated by [gtk-query-immodules-3.0][gtk-query-immodules-3.0], in order for the new input method to become available to GTK+ applications.

Hierarchy

hierarchy this GtkIMContext ancestor_0 GObject ancestor_0--this

Ancestors

Instance methods

gtk_im_context_delete_surrounding

Asks the widget that the input context is attached to to delete characters around the cursor position by emitting the GtkIMContext::delete_surrounding signal. Note that offset and n_chars are in characters not in bytes which differs from the usage other places in GtkIMContext.

gtk_im_context_filter_keypress

Allow an input method to internally handle key press and release events. If this function returns TRUE, then no further processing should be done for this key event.

gtk_im_context_focus_in

Notify the input method that the widget to which this input context corresponds has gained focus. The input method may, for example, change the displayed feedback to reflect this change.

gtk_im_context_focus_out

Notify the input method that the widget to which this input context corresponds has lost focus. The input method may, for example, change the displayed feedback or reset the contexts state to reflect this change.

gtk_im_context_get_preedit_string

Retrieve the current preedit string for the input context, and a list of attributes to apply to the string. This string should be displayed inserted at the insertion point.

gtk_im_context_get_surrounding

Retrieves context around the insertion point. Input methods typically want context in order to constrain input text based on existing text; this is important for languages such as Thai where only some sequences of characters are allowed.

gtk_im_context_reset

Notify the input method that a change such as a change in cursor position has been made. This will typically cause the input method to clear the preedit state.

gtk_im_context_set_client_window

Set the client window for the input context; this is the GdkWindow in which the input appears. This window is used in order to correctly position status windows, and may also be used for purposes internal to the input method.

gtk_im_context_set_cursor_location

Notify the input method that a change in cursor position has been made. The location is relative to the client window.

gtk_im_context_set_surrounding

Sets surrounding context around the insertion point and preedit string. This function is expected to be called in response to the GtkIMContext::retrieve_surrounding signal, and will likely have no effect if called at other times.

gtk_im_context_set_use_preedit

Sets whether the IM context should use the preedit string to display feedback. If use_preedit is FALSE (default is TRUE), then the IM context may use some other method to display feedback, such as displaying it in a child of the root window.

Methods inherited from GObject (42)

Properties

Gtk.IMContext:input-hints
No description available.
Gtk.IMContext:input-purpose
No description available.

Signals

Gtk.IMContext::commit

The ::commit signal is emitted when a complete input sequence has been entered by the user. This can be a single character immediately after a key press or the final result of preediting.

Gtk.IMContext::delete-surrounding

The ::delete-surrounding signal is emitted when the input method needs to delete all or part of the context surrounding the cursor.

Gtk.IMContext::preedit-changed

The ::preedit-changed signal is emitted whenever the preedit sequence currently being entered has changed. It is also emitted at the end of a preedit sequence, in which case gtk_im_context_get_preedit_string() returns the empty string.

Gtk.IMContext::preedit-end

The ::preedit-end signal is emitted when a preediting sequence has been completed or canceled.

Gtk.IMContext::preedit-start

The ::preedit-start signal is emitted when a new preediting sequence starts.

Gtk.IMContext::retrieve-surrounding

The ::retrieve-surrounding signal is emitted when the input method requires the context surrounding the cursor. The callback should set the input method surrounding context by calling the gtk_im_context_set_surrounding() method.

Signals inherited from GObject (1)

Class structure

struct GtkIMContextClass {
  void (* preedit_start) (
    GtkIMContext* context
  );
  void (* preedit_end) (
    GtkIMContext* context
  );
  void (* preedit_changed) (
    GtkIMContext* context
  );
  void (* commit) (
    GtkIMContext* context,
    const gchar* str
  );
  gboolean (* retrieve_surrounding) (
    GtkIMContext* context
  );
  gboolean (* delete_surrounding) (
    GtkIMContext* context,
    gint offset,
    gint n_chars
  );
  void (* set_client_window) (
    GtkIMContext* context,
    GdkWindow* window
  );
  void (* get_preedit_string) (
    GtkIMContext* context,
    gchar** str,
    PangoAttrList** attrs,
    gint* cursor_pos
  );
  gboolean (* filter_keypress) (
    GtkIMContext* context,
    GdkEventKey* event
  );
  void (* focus_in) (
    GtkIMContext* context
  );
  void (* focus_out) (
    GtkIMContext* context
  );
  void (* reset) (
    GtkIMContext* context
  );
  void (* set_cursor_location) (
    GtkIMContext* context,
    GdkRectangle* area
  );
  void (* set_use_preedit) (
    GtkIMContext* context,
    gboolean use_preedit
  );
  void (* set_surrounding) (
    GtkIMContext* context,
    const gchar* text,
    gint len,
    gint cursor_index
  );
  gboolean (* get_surrounding) (
    GtkIMContext* context,
    gchar** text,
    gint* cursor_index
  );
  void (* _gtk_reserved1) (
void
  );
  void (* _gtk_reserved2) (
void
  );
  void (* _gtk_reserved3) (
void
  );
  void (* _gtk_reserved4) (
void
  );
  void (* _gtk_reserved5) (
void
  );
  void (* _gtk_reserved6) (
void
  );
  
}
Class members
preedit_start
void (* preedit_start) (
    GtkIMContext* context
  )
  No description available.
preedit_end
void (* preedit_end) (
    GtkIMContext* context
  )
  No description available.
preedit_changed
void (* preedit_changed) (
    GtkIMContext* context
  )
  No description available.
commit
void (* commit) (
    GtkIMContext* context,
    const gchar* str
  )
  No description available.
retrieve_surrounding
gboolean (* retrieve_surrounding) (
    GtkIMContext* context
  )
  No description available.
delete_surrounding
gboolean (* delete_surrounding) (
    GtkIMContext* context,
    gint offset,
    gint n_chars
  )
  No description available.
set_client_window
void (* set_client_window) (
    GtkIMContext* context,
    GdkWindow* window
  )
  No description available.
get_preedit_string
void (* get_preedit_string) (
    GtkIMContext* context,
    gchar** str,
    PangoAttrList** attrs,
    gint* cursor_pos
  )
  No description available.
filter_keypress
gboolean (* filter_keypress) (
    GtkIMContext* context,
    GdkEventKey* event
  )
  No description available.
focus_in
void (* focus_in) (
    GtkIMContext* context
  )
  No description available.
focus_out
void (* focus_out) (
    GtkIMContext* context
  )
  No description available.
reset
void (* reset) (
    GtkIMContext* context
  )
  No description available.
set_cursor_location
void (* set_cursor_location) (
    GtkIMContext* context,
    GdkRectangle* area
  )
  No description available.
set_use_preedit
void (* set_use_preedit) (
    GtkIMContext* context,
    gboolean use_preedit
  )
  No description available.
set_surrounding
void (* set_surrounding) (
    GtkIMContext* context,
    const gchar* text,
    gint len,
    gint cursor_index
  )
  No description available.
get_surrounding
gboolean (* get_surrounding) (
    GtkIMContext* context,
    gchar** text,
    gint* cursor_index
  )
  No description available.
_gtk_reserved1
void (* _gtk_reserved1) (
void
  )
  No description available.
_gtk_reserved2
void (* _gtk_reserved2) (
void
  )
  No description available.
_gtk_reserved3
void (* _gtk_reserved3) (
void
  )
  No description available.
_gtk_reserved4
void (* _gtk_reserved4) (
void
  )
  No description available.
_gtk_reserved5
void (* _gtk_reserved5) (
void
  )
  No description available.
_gtk_reserved6
void (* _gtk_reserved6) (
void
  )
  No description available.

Virtual methods

Gtk.IMContextClass.commit
No description available.
Gtk.IMContextClass.delete_surrounding

Asks the widget that the input context is attached to to delete characters around the cursor position by emitting the GtkIMContext::delete_surrounding signal. Note that offset and n_chars are in characters not in bytes which differs from the usage other places in GtkIMContext.

Gtk.IMContextClass.filter_keypress

Allow an input method to internally handle key press and release events. If this function returns TRUE, then no further processing should be done for this key event.

Gtk.IMContextClass.focus_in

Notify the input method that the widget to which this input context corresponds has gained focus. The input method may, for example, change the displayed feedback to reflect this change.

Gtk.IMContextClass.focus_out

Notify the input method that the widget to which this input context corresponds has lost focus. The input method may, for example, change the displayed feedback or reset the contexts state to reflect this change.

Gtk.IMContextClass.get_preedit_string

Retrieve the current preedit string for the input context, and a list of attributes to apply to the string. This string should be displayed inserted at the insertion point.

Gtk.IMContextClass.get_surrounding

Retrieves context around the insertion point. Input methods typically want context in order to constrain input text based on existing text; this is important for languages such as Thai where only some sequences of characters are allowed.

Gtk.IMContextClass.preedit_changed
No description available.
Gtk.IMContextClass.preedit_end
No description available.
Gtk.IMContextClass.preedit_start
No description available.
Gtk.IMContextClass.reset

Notify the input method that a change such as a change in cursor position has been made. This will typically cause the input method to clear the preedit state.

Gtk.IMContextClass.retrieve_surrounding
No description available.
Gtk.IMContextClass.set_client_window

Set the client window for the input context; this is the GdkWindow in which the input appears. This window is used in order to correctly position status windows, and may also be used for purposes internal to the input method.

Gtk.IMContextClass.set_cursor_location

Notify the input method that a change in cursor position has been made. The location is relative to the client window.

Gtk.IMContextClass.set_surrounding

Sets surrounding context around the insertion point and preedit string. This function is expected to be called in response to the GtkIMContext::retrieve_surrounding signal, and will likely have no effect if called at other times.

Gtk.IMContextClass.set_use_preedit

Sets whether the IM context should use the preedit string to display feedback. If use_preedit is FALSE (default is TRUE), then the IM context may use some other method to display feedback, such as displaying it in a child of the root window.